There are then, at least two dialectical truths. The first is that you and I are reasonable creatures; the second that you and I ought to be reasonable. Because of the second, we can say not merely that we cannot reasonably deny the first, but also that we ought not to deny it. If these dialectical propositions are errors, they are irrefutable errors: there is no way for men qua rational creatures to find out what is wrong with them, just as there is no way for men qua rational creatures to cast doubt on their truth.